The successful purification, partial characterization, and quantification of two human neutrophil proteinases, elastase (HNE) and cathepsin G (HNCG) and the identification of a neutrophil specific collagenase (HNC) has clearly defined the neutrophil as a major source of proteinases potentially capable of producing tissue damage in acute inflammatory processes such as rheumatoid arthritis. Although in vitro studies demonstrating cleavage of connective tissue structural macromolecules by purified HNE and HNCG and partially purified HNC underlie their potential pathogenic role in tissue destruction, their true in vivo role in rehumatoid arthritis remains unknown. We propose to investigate this possibility by accurately quantitating these proteinases in rheumatoid synovial fluid. These studies will be extended to study mechanisms of proteinase release in neutrophils. Specifically, we will: 1) Purify HNC and human neutrophil myeloperoxidase (HNM) and improve purification methods for HNE amd HNCG. 2) Raise monospecific antisera antibodies which react with the neutroohil proteinases and the granule marker protein. 3) Determine the immunochemical quantity of the three neutrophil proteinases, the azurophil granule marker, myeloperoxidase and the specific granule marker, lactoferrin by radioimmunoassay and measure the enzymatic activity of the three proteinases in the synovial fluid of patients with rheumatoid arthritis. 4) Investigate the differential release of these three proteinases and granule markers induced by immune complexes from the neutrophils of normal volunteers and patients with rheumatoid arthritis 5) Investigate the interaction of these proteinases with intact articular cartilage. These studies willnot only enhance our understanding of pathways of extracellular degranulation of human neutroohil azurophil and specific granules induced by immune complexes but also give insight into mechanisms of in vivo tissue injury such as that occurring within the rheumatoid joint.